Thermostatic regulator



Feb. 23,1926. r 1,574,479

J. A. GUYER THERMOSTATI C REGULATOR Filed March 50, 1925 .1 1216 22511 Joacpk Ji. Guyci;

Patented Feb. 23, 1 926.. i uNiEi s TEs JOSEPH A. GUYER, or

r THEnMosrATIo REGULATOR.

PATENT OFFICE.)

MARION, INDIANA, ASSIGNOR 0F ONE-HALF 'ro IIAImYr.

ANDERSON, or MARION, INDIANA.

Application filed March so, 1925. Serial No. 19,523.

To'alll whom it concern:

Be it known that I, JosErI A. GUYER, a citizen .of the United States, residing at Marion, in the county of Grant and State of Indiana, have invented a certain new and useful Thermostatic Regulator, of which th following is a specification.

This invention relates to thermostatic regulators and especially to one which involves a timing of counting device, that acts also as a' safety device when necessary for outting off the heat being supplied. The invention is especially applicable to ovens 1 wherein a certain degree of heat is required .vide in said device a timing feature operable to limit the number of times that the regulator acts and to assure that the device ceases operation with the heatcut oif.

Various other objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings in which Figure 1 illustrates the face of the de-' vice'showing a control dial thereon.

Fig. 2 is a detailed view of the device showing the spring motive means.

Fig. 3 is a cross sectional view of the device showing the assembly arrangement of the parts.

Fig. 4 is across sectional horizontal view on the line H of Fig. 3.

Fig. 5 is a detail view of the mounting of one of the parts, the view being taken on the line 55 of Fig. 3.

While I have shown in the drawings and will herein describe in detail the preferred embodiment of the invention, I desire to have it understood that this disclosure is given for the purpose of representing but one specific wayof carryingout the invention and is not intended as a limitation thereof to the construction disclosed. I aim to cover in the appended claims all modifications and alternative constructions fall ing within the scope of the'invention as limited b the state of the prior art.

In the rawings I show the device attached to an electric cooker, the device, of course, being particularly adapted for this purpose and being admirably suited for its requirements. Electric cookers are constructed to give a much higher degree of heat than is ordinarily required so that on initial heating the oven rapidly comes up to temperature permitting current to be cut off, whereafter the oven gradually cools down slowly because of its insulating construction. For long-time cooking, as for roasts and the like, it may be necessary to turn the heat on and off several times to maintain the oven. at the proper temperature for a sufficiently long time.v In other cases but one cut-offof the heating current may be sufiicient. The present device is arranged to be set for a predetermined number of cut-offs which are roughly proportional tothe time required for cooking some particular food. This permits one to place the food in the oven, to set the device and to leave itwithout further thought or attention.

The device in the .drawings is contained ina box 6 which is fastened to one side of an oven 7. An expansible thermal element is provided and arranged to be'heated by the heat in the oven and to operate the heat controlling electric switch. In the present instance the thermal element is a vent pipe 8 through which heat escapes from the lining of the oven. The thermalelement is a tubular member having a right angled end 9 securedby a flange 10gto the back of box 6 and communicating with the oven interior through the passage 11. The vent :pipe has its other end free and unsecured,being provided with a laterally extending open tube 12 near the free end. Tube 12 projects through an opening l2 in-the front of the box 6'."

The free end carriesa contact tip 13 thereon which, of course, moves longitudinally with reference to the fixed end of the vent pipe as it expands and contracts. A stop member in the form of a lever 14 is pivoted at 15 adj acent the tip 1.3, the lever being moved by a spring 16- tending to hold it constantly against the tip 13 as the pipe 8 expands and contracts in length by the change in the temperature of the oven.

The tube 8 is arranged to cut 0d the ourrent when expansion has taken place to a predetermined point and likewise to turn on the current when contraction to another predetermined point has taken place. In the present instance theelectric switch"provided "is contained in an insulating casing 17 of bakelite or other suitablennaterial, the switch being secured within the cir'cuitbox 6. A fixed contact 18 is mounted in'the bottom of the switch casing and a movable contact 19 is mounted in the topiof 'the switch casing. Wires 20 lead to these contacts. Contact 19 is carried by aplunger 21 movably-mounted in the cover 22 of the switch casing. A coil spring 23 surrounds the plungeryis connected to one of the wires 20 -a't the. binding post 24, and operates to move the contacts into electrical engagement. A short length of insulating material in the form of a link 25 connects the plunger to a bar 26 pivoted at 27 to a metallic strip. 28 secured to the box and oven. Link I 25 hastwo holes 29 and 29 therein adapted for'pivotal connection to the bar 26. When a hole 29 is used the contacts maybe emersed in oil to quench the arcing caused by separating the contacts. \Vhen hole 29 is used the contacts do not meet and a quantity of mercury or mercury and oil maybe used in the switch case to provide a. mercury switch ifthis is desirable. j

The means provided to operate the switch in'the present instance is a motive means tending to move past the lever 14 and constrained thereby against motion. -Upon a motion in the proper direction of the lever 14 as required by the heat status'of the oven,

and ratchet embodied allin a single wheel 30' .rigid with a shaft 31. The wheel has a plurality of ratchet teeth of two types 32 and 33 placed alternately about the periphery of the wheel 30. Teeth 32 are longer in a 'radial direction than the teeth 33 and have 7 bringing the longer tooth 32 against the ler for operating the switch as the wheel is thus ver'pin or end 35.

A cam groove 36 is formed in the'wheel moved tooth by tooth. A tooth 32 is positioned against the end ofthe lever 14 when the. switch is opened and a tooth 33 is positioned at the end of the lever when the switch is closed. A cam roller 37 on thebar 26 follows the groove to operate the switch.

In the presentfinstan'ce there are sixteen teeth corresponding to eight teeth for openmg and eight teeth for closing the switch the lever permits motion to operate the nate teeth. 'A clock spring 38 secured at one end to'the shaft 31 and at the other end to the 'back' of the circuit box asat 39 serves toactuate the wheel .30 counterclockwise in Fig. 3. i i

A timing or counting device .is provided to limit the number of times which the regulator will turn the heat on and off. The

device is capable of manual setting to limit 1 the number of times the heat is turned on and off. As this is controlled by the so that the cam contour repeats with altertemperature of the oven, which is in 7 turn dependent upon its heat radiating properties, it follows that for any particular oven the counting device is primarily a timing device. v v

The shaft extends through the circuit box 6 and is provided with a crank handle 40' of the wheel 30 by stopping the crank-40.

A second pin 43 may be positioned in any hole of the dial and is herein shown located in position 4 so that after the corresponding number of shut-offs (in the present instance four) the device will cease'operation.

To operate the device one merely puts pin 43 into the hole corresponding to the time required for cooking. ,Suppose for this particular ,oven, one shut-ofi takes place every fifteen minutes and that about one hour is required for cooking. Then the operator' will place the loose pin 43 in position 4 on the dial and turn; the crank 40 clockwise against the stop pin 42 thus winding the spring' 385 The spring 16 permits the ratchet teeth to move lever 14 out of the way in the Winding process. Current will be on in this position of thelever. VVhenthe thermal element 8 expands it will push lever 14 away from the under side of tooth 33 whereupon wheel 30 will turn bringing the longer tooth 32 against the end of the lever at the same time opening the circuit through the action of the cam groove 36 upon thecam bar 26. As the oven cools down the thermostatic element 8 contracts- As the oven heats up and cools down there will have been four periods of heatin and four cut-oils in the current. After th fourth cut-off the handle 40will lie against the pin 48 thus preventing further opera-- It will' be noted that,

tion of the device. the holes in the dial are so positioned tha the device always comes to rest in they olf position of the electric switch so that when the predetermined time of cooking has elapsed the device willautomatically shut off and require no attentlon on thepart of eration for atleast eight cut-offs of the current. i If the device operates for fifteen I minutes on one heating there will never be more than two' hours during which the oven will be in operation because of failure of the operator to attend to the same. Thus, the pin 42 serves as a safety device for the apparatus.

In the above illustration while I have shown an electric switch as the means for controlling the supply of heat, it is obvious that this may be connected to operate an electric or other source-'of'heat and that it may be substituted by other means so that the mere action of the cam bar 26 instead of operating'the switch will serve to cut in or out any heat supply which it is preferable to use. Likewise, it will be understood that the length of the thermostatic element may be varied as well as its relatiop to lever 14 so as to control-the degree 0 heat required. But it will be understood "that these improvements are well known expedients which I have. not deemed it necessary to embody in the present disclosure.

I. claim as my invention: 1. A heat regulator comprising, in' combination, an electric'switch operable to'control a supply of heat, a thermal expansion element affected by the heat sup ly, a lever arranged to bemoved by said t ermal element as it contracts and expands, resilient means holding said lever against said element, a ratchet wheel having teeth adapted to rest against said lever, said ratchet having two sets of teeth, one set being longer radially than the other and said long teeth having a channel therein to permit the passage therethrough of the end of said lever, means to rotate the. wheel, a cam on said wheel, and a cam bar to operate the switch, said cam being arranged to throw the switch when the .wheel moves the distance of one tooth.

2. A heat regulator comprising, in combination, an electric switch operable to control the supply of heat, a thermal expansion element aifected by the heat supply, a lever arranged to be moved bysaid thermal ele-' ment as it, contracts and expands, resilient means holding said lever against said element, a ratchet wheel having teeth adapted to rest against said lever, saidratchet having two sets of teeth, one set being longer \radially than the other and said long teeth having a channel therein to permit the passage therethrough. of the end of said lever, means to rotate the wheel, a cam on said wheel, a cam bar to operate the switch, said cam being arranged to throw the switch when the wheel moves the distance of one tooth, and means to limit the number of tooth spaces moved bysaid wheel.

3. A heat regulator for an oven and the like comprising, 'in combination, a thermo stat, a movable member,-means to move said member,ratchet teeth on said member, a stop member engaging said ratchet teeth and arranged to be moved by the thermostat, alternate teeth on said movable member projecting beyond the other teeth and having a groove therein inwardly thereof, whereby the stop member may pass relatively by the short ,teeth and through the groove of the long teeth, and means operated by said movable member to shut off and turn on alternately a heat supply with the advance of one tooth. 4. A heat regulator for an oven and the like comprising, in combination, a thermostat, a movable member, means to move said member, ratchet teeth on said member, a

stop member engaging said ratchet teeth and arranged to be moved by the thermostat, alternate teeth on said movable member pro-' jecting beyond the other teeth and having a groove therein inwardly thereof, whereby the stop member may pass relatively by the. short teeth and through the gropve of the long teeth, a cam on said movable member repeating its form between alternate teeth, andmeans moved by said cam to control a heat supply. 5. A heat regulator for an oven and the like comprising, in combination a thermostatic element. a lever moved by said element, a movable element, two sets of ratchet teeth arranged-tohold the member against motion past said lever, said teeth being further arranged so thatmotion of the lever 'to permit passage of a tooth in one set brings the lever against, a tooth in another set, and means operated by said movable member to open a heat supply upon release 1 of a tooth of one set and to close said heat supply on the release of a tooth of the other set. i

6. A heat regulator for an oven andthe like comprising, in combination a movable member, means to move said member, two

sets of ratchet teeth on said member, a thermostatic element arranged on contraction andexpansion to release a ratchettooth of d 11. A heat regulator for an oven comone set and to hold a ratchet tooth ofthe prising, in combination, a thermostat, an other set whereby the movable member adelectric sw tch for controlling J the heat vances tooth by tooth, an electric switch, afi'ectmg sald thermostat, motive means inwith each advance to open and close an elecstat to operate the switch according to the ,trio CllTQllll) controlling a heat supply.

7 In a device of the class described havgiven heat, and'means to limit the operation ing a spring actuated member rotating step of. said motive means to more than one heatby step and arranged to turn on and ofi the Tcutting-ofi operation of the switch. heat supply to maintain a prolonged heat, '12. A heat regulator for an oven coma handle on said member, a dial over which prising, in combination, a thermostat, an said handle moves, said dial having a plu- .electric switch for controlling the heat rality of holes therein positioned in the afi'ecting said thermostat, motive means inpath of the handle in' the ofl'f condition of terposed betweenf the switch and the thenthe heat, and a in adapted to be inserted mostat to-operate the switch according to in any one of said holes tolimit the numthe conditions of the thermostat to mainber of operations for stopping the device tain a given heat, means to limit the oper with the heat shut ofi. ation of said motive means to more than one thereon arranged alternately, the teeth of position of the heat.

one set projecting beyond the tips of the 13. A'heat regulator for an oven and the groove, a) member arranged to hold said static element, a movablestop-member conratchet teeth against motion said member trolled by said element, a motive device, two

' ibeing adapted to move'outof the way of sets of teeth arranged on said motive dcthe short teeth and to move into the groove vice to hold said device against motion past of the long teeth to permit motion of the the stop-member, said teeth being further wheel. K arranged so that motion of the stop-member '9. In a device of the character'described, to permit passage) of a tooth in one set a ratchet wheel having two kinds of teeth brings the stop member against a tooth in I thereon arranged alternately, the teeth of the other set, and means controlling a heat one set projecting beyond the tips of the. supply affecting said thermostatic element, teeth of the other set and having therein a said means being controlled by one of said groove, a member arranged to. hold said movable parts to open said heat supply upon ratchet teeth against motion, said member release of a tooth in one set and to close said being adaptedto move in one direction out heat of the way of the short teeth and to move set. back into the groove of the long teeth to 14.

permit motion of the wheel, an electric like comprising, in combination, a'thermoswitch, and a cam on said wheel arranged to static element, a movable stop-member con- I effect opening and .closing alternately of trolled by said element, a motivedevicatwe said electric \switch as the wheel advances ests of teeth-arranged on said motive device past said member, the current controlled by .to hold said device against motion past the said switch being efi'ective to cause motion 7 of the movable member.

ranged so that motion of the stop-member conditions-ofrthe thermostat to maintain a' 8. In a device of the character described, operationof the switch, and means to effect a ratchet wheel having two kinds of. teeth stoppingof the motive means in the off I teeth of the other set and having therein a like comprising, in combination, a thermo-- supply on release of a toothin' the other.

iso

10. Ina device of the class described hav-' ing a thermostat and a heat controlling elec- Y tric switch, in combination, movable. means associated-with said thermostat andswitch, said means being moved at each instance of heat-cutting-ofi action, and means associated with said movable means adapted to limit the number of heat-'cntting-ofi act-ions ofsaid switch to a predetermined number more than one. 4

to permit passage of a tooth in one set/brings the stop member against a tooth in the other set, means controlling a heat supply ,afiecting said thermostatic element, and counting and means to operate said electric switch terposed between the switch and the thermo- A heat regulator for an oven and the stop-member, said teeth being further armeans arranged to be set for limiting the 5 number of teeth released after any one setting.

In, testimony whereof, I have hereunto affixed nrv signature.

JOSEPH A. Y'GUYER. 

